1. Field
The present disclosure relates to a beam current density distribution adjustment device that locally deflects a ribbon beam to adjust beam current density distribution in a long side direction of the beam, and to an ion implanter including the beam current density distribution adjustment device.
2. Description of the Related Art
A device that uses an electric field or a magnetic field to adjust beam current density distribution in a long side direction of a ribbon beam is known.
Examples of the device using an electric field may include devices illustrated in Japanese Patent Laid-Open Application No. 2014-183042. In these devices, a plurality of electrode pairs are disposed along the long side direction of the ribbon beam. Electrodes of each of the electrode pairs are oppositely disposed with the ribbon beam in between. To locally deflect a beam component to adjust the beam current density distribution in the long side direction of the ribbon beam, voltages to be applied to respective electrode pairs that are arranged in the long side direction of the ribbon beam are adjusted.
Examples of the device using a magnetic field may include a device illustrated in Japanese Patent Laid-Open Application No. 2005-327713. In the device, a plurality of magnetic pole pairs are disposed along the long side direction of the ribbon beam. Magnetic poles of each of the magnetic pole pairs are oppositely disposed with the ribbon beam in between. Each magnetic pole is wound with a coil. To locally deflect a beam component to adjust the beam current density distribution in the long side direction of the ribbon beam, currents to the coils wound around the respective magnetic poles, of the magnetic pair, opposed to each other in a short side direction of the ribbon beam are adjusted.
Further, as the example of the device using a magnetic field, devices illustrated in the National Publication of International Patent Application No. 2005-533353 are also known. In the devices, a plurality of coils are wound around a rectangular-shaped yoke having an opening through which the ribbon beam passes. To locally deflect a beam component to adjust the beam current density distribution in the long side direction of the ribbon beam, a direction of a current flowing through the plurality of coils wound around one of opposing long shafts of the yoke is opposite to that of the other shaft, and currents to the respective coils are adjusted.